Three samples of known concentration were tested twenty times on one plate to assess.

Inter-assay Precision (Precision between assays): CV%<10%

Three samples of known concentration were tested in twenty assays to assess.

Linearity

To assess the linearity of the assay, samples were spiked with high concentrations of human IDO in various matrices and diluted with the Sample Diluent to produce samples with values within the dynamic range of the assay.

Sample

Serum(n=4)

1:1

Average %

90

Range %

85-99

1:2

Average %

95

Range %

91-102

1:4

Average %

89

Range %

84-94

1:8

Average %

93

Range %

89-98

Recovery

The recovery of human IDO spiked to levels throughout the range of the assay in various matrices was evaluated. Samples were diluted prior to assay as directed in the Sample Preparation section.

Sample Type

Average % Recovery

Range

Serum (n=5)

97

91-104

EDTA plasma (n=4)

86

80-90

Typical Data

These standard curves are provided for demonstration only. A standard curve should be generated for each set of samples assayed.

We discuss how small-molecule inhibitors of the tryptophan (Trp) catabolic enzyme indoleamine 2,3-dioxygenase (IDO) represent a vanguard of new immunometabolic adjuvants to safely enhance the efficacy of cancer immunotherapy, radiotherapy, or 'immunogenic' chemotherapy by leveraging responses to tumor neoantigens PMID: 29413421

The role of IDO1-IDO2-AHR pathway in the TLR4-induced tolerogenic phenotype in human dendritic cells has been reported. PMID: 28256612

High coexpression of cytoplasmic IDO1/COX2 was found to be an independent predictor of poor outcome in colorectal cancer patients. PMID: 29853736

Report the crystal structures of IDO1 in complex with its substrate, Trp, an inhibitor, epacadostat, and/or an effector, indole ethanol (IDE). The data reveal structural features of the active site (Sa) critical for substrate activation; in addition, they disclose a new inhibitor-binding mode and a distinct small molecule binding site (Si). PMID: 29167421

this review highlights the role of indoleamine-2,3-dioxygenase in normal and pathological pregnancies PMID: 29154462

Data suggest that IDO1 is constitutively expressed in insulin-secreting cells from donors without diabetes; IDO1 appears to be down-regulated in insulin-containing beta-cells from double autoantibody-positive donors and donors with recent-onset type 1 diabetes; this study was conducted on donor tissues obtained from cadavers. PMID: 29945890

In non-ST segment elevation myocardial infarction, the tolerogenic mechanism of the immune response related to IDO production by activated monocytes derived dendritic cells is altered, supporting their role in T-cell dysregulation. PMID: 29278387

These data suggest that the expression of immunosuppressive molecules, including PD-1 ligands and IDO1, by macrophage/microglia may be involved in immune evasion of lymphoma cells. PMID: 29998979

these findings suggest that IDO1 promoter methylation regulates anti-immune responses in breast cancer subtypes and could be used as a predictive biomarker for IDO1 inhibitor-based immunotherapy. PMID: 28264810

main biological and actionable difference between OSCC from NSND and SD lies in the immune microenvironment, suggesting a higher clinical benefit of PD-L1 and IDO1 inhibition in OSCC from NSND PMID: 28460011

Fumaric acid esters inhibit both IDO expression and enzymatic activity leading to a modulation of tryptophan degradation. PMID: 27376248

Our results highlight the role of COX-2 in constitutive IDO1 expression by human tumors and substantiate the use of COX-2 inhibitors to improve the efficacy of cancer immunotherapy, by reducing constitutive IDO1 expression, which contributes to the lack of T-cell infiltration in "cold" tumors, which fail to respond to immunotherapy PMID: 28765120

this data we have identified the structure of two possible compounds that may be even more potent pharmacological repressors of IDO-1. PMID: 28735627

These findings indicate that IDO1 has the potential to participate in or contribute to the formation of new capillaries, supporting the applicability of IDO1-targeting molecular therapy in lung cancer. PMID: 28498425

PD-L1, IDO-1, and B7-H4 are differentially expressed in human lung carcinomas and show limited co-expression. While PD-L1 and IDO-1 are associated with increased tumor-infiltrating lymphoycte and IFN-gamma stimulation, B7-H4 is not. PMID: 27440266

MALAT1-overexpressed MSCs promoted M2 macrophage polarization and this effect was mediated by MALAT1-induced IDO expression, suggesting that MALAT1 may enhance the immunosuppressive properties of MSCs in vivo. PMID: 28176360

this study demonstrated that the downregulation of IDO expression on the endothelial cells of the villous stroma was associated with preeclampsia PMID: 28131097

The data suggest that in Puumala infection, the mechanism responsible for the suppressive effect of IDO is not metabolic control of effector cells but rather the signaling mediated by tryptophan breakdown products, such as kynurenine. PMID: 28057727

These results show IDO is upregulated with RSV infection and this upregulation likely participates with IFN-gamma in inhibition of virus replication and suppression of some host cell responses to infection. PMID: 28963880

The aim of the present study was to clarify the effect of IDO1induced macrophages on the growth of endometrial stromal cells in endometriosis. IDO1 educated-macrophages may facilitate the survival of retrograde endometrial tissues, and be involved in the pathogenesis of endometriosis. PMID: 28260094

Our results identified FGL2, GAL, SEMA4D, SEMA7A, and IDO1 as new candidate genes that could be involved in MSCs-mediated immunomodulation. FGL2, GAL, SEMA4D, SEMA7A, and IDO1 genes appeared to be differentially transcribed in the different MSC populations. Moreover, these genes were not similarly modulated following MSCs-exposure to inflammatory signals PMID: 28336906

The study confirmed that high IDO expression in pancreatic adenocarcinoma was related to poor prognosis of patients. These findings provided evidence that IDO was involved in pancreatic adenocarcinoma progression and might serve as a relevant therapeutic target. PMID: 28303855

ver-expression of CTLA4 and IDO1 was significantly associated with biochemical recurrence. Our results provide clues on the mechanisms of tumor development and point to potential biomarkers for early detection and treatment for prostate cancer in young men. PMID: 28027300

These results indicate that the level of IDO expression may be associated with pregnancy-related complications, such as URSA, by affecting trophoblast cell proliferation and migration via the STAT3 signaling pathway. PMID: 26814137

IDO is a potential prognostic biomarker for overall survival of patients with gastric adenocarcinoma after gastrectomy. PMID: 26887337

IDO expressed by placenta cells can down-regulate NKp46 and NKG2D expression and reduce cytotoxicity in NK cells, suggesting an important role for IDO in the maintenance of normal pregnancy PMID: 26782048

Results suggest that IDO expression is implicated in immunosuppression and tumor progression in glioma cells; combining IDO inhibition with standard TMZ treatment could be an encouraging therapeutic strategy for patients with malignant glioma PMID: 26636389

Our results imply the probability of involvement of IDO in development of tolerance process, and we presume that high IDO activity is associated with nonresponsiveness to food allergens despite allergen sensitization. PMID: 26449488

IDO, through GCN2 kinase activation, downregulates the levels of TCRcomplex tchain and cMyc, resulting in the suppression of Tcell proliferation and a reduction in the levels of LDHA and GLS2 PMID: 26647830

ISG15 is elevated in viremic HIV-1 patients and is associated with high TRAIL and IDO levels. PMID: 26563749

IDO1 expression and activity in LC seem to be involved in the pathophysiology of EH in AD and could represent a predictive biomarker for patients with risk to develop EH and other viral complications. PMID: 26198597

MT has potentiating effect in TGF-beta1-induced EMT, independently of IDO. This nonimmunological effect of MT should be considered if IDO is the target to avoid immune escape in bladder cancer PMID: 26267811

The data are consistent with a common reaction mechanism for indoleamine 2,3-dioxygenase-catalyzed oxidation of tryptophan and other tryptophan analogues. PMID: 26511316

Downregulation of CD4 expression by IDO was significantly attenuated by the addition of tryptophan or IDO inhibitor in the infected C8166 cells. PMID: 23109825

Results show low expression of Bin1, along with high expression of IDO, are predictor for poor prognosis in esophageal squamous cell cancer and thereby could be used to establish new therapeutic strategies. PMID: 25683635

We found a definitive relation between IDO1 induction on acute myeloid leukemia blasts mediated by NK cell-produced IFNgamma and the consequent functional deregulation of NK cells that favors AML immune escape. PMID: 25886742

RSV can induce the expression and bioactivity of IDO in human moDC, in a virus replication-dependant fashion. We suggest that RSV activation of IDO could be a potential mechanism for the development of allergic diseases. PMID: 25627660

IDO and tryptophan derivatives, particularly tranilast, can be tools for the therapy for lymphoid malignancies. PMID: 25572287

Data suggest that the tumor necrosis factor-alpha (TNF-alpha)/ transforming growth factor-beta (TGF-beta)/indoleamine 2,3-dioxygenase (IDO) axis may represent a new mechanism contributing to the development of tolerance in IVIg-treated patients. PMID: 25461397

The results suggest that considering IDO and EGFR as two indicators for breast cancer treatment or prognosis analysis provides a potential option of individual treatment for the portion of breast cancer patients with co-expression of IDO and EGFR. PMID: 25081660

through the activation of IL-33, the increased expression of IDO1 in ectopic endometrial stromal cells contributed to the truncated phagocytic ability of macrophages in endometriosis. PMID: 25031694

Cell-sorting experiments demonstrated that IDO1 expression is found in a subset of CD1a(+)CD14(-)langerin(+) cells, expressing CD103 PMID: 25584868

antimicrobial functions are found to be species- and pathogen-specific PMID: 23940074

indoleamine 2,3-dioxygenase and infiltration of FOXP3+ regulatory T cells may have a role in aggressive characteristics of papillary thyroid microcarcinoma PMID: 24742251

Induction of IDO was mediated by the same TLR7-dependent recognition of B. burgdorferi RNA that contributes to the production of type I IFNs by human DCs. PMID: 25420916

In order to exert their protolerogenic function, fibrocytic myeloid-derived suppressor cells require direct contact with activated T cells, which leads to the production and secretion of IDO. PMID: 25113564

These results demonstrate that IDO2 plays a novel role as a negative regulator of IDO1 by competing for heme-binding with IDO1. PMID: 25394548

Data show that the subsets of dendritic cells and memory T cells, and the indoleamine 2,3-dioxygenase (IDO) expression were correlated with each other with the tumor size, depth of invasion, lymph node metastasis, and clinical stage. PMID: 24870595

RelB-p52 dimers were found to directly bind to the IDO promoter, leading to IDO expression in MDSCs PMID: 25063873

Paradoxical upregulation of IDO expression in colon MNCs and ECs may represent a new predictive factor for prognosis in gut AGVHD after human allogeneic hematopoietic stem cell transplantation. PMID: 24732701

IDO was found in association with circulating breast cancer MV, while experimental and in silico gene expression revealed that IDO was mainly expressed in a triple-negative subgroup. PMID: 24687552

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Subcellular Location

Cytoplasm, cytosol

Protein Families

Indoleamine 2,3-dioxygenase family

Tissue Specificity

Expressed in mature dendritic cells located in lymphoid organs (including lymph nodes, spleen, tonsils, Peyers's patches, the gut lamina propria, and the thymic medulla), in some epithelial cells of the female genital tract, as well as in endothelial cell